Enhanced nonlinear optics in photonic-crystal microcavities

TLDR

Nonlinear photonic‑crystal microresonators uniquely enhance nonlinear optical processes, enabling lower operation powers and faster switching suitable for realistic ultrafast integrated devices. We review three nonlinear optical phenomena that can be strongly enhanced in photonic crystal microcavities. The review discusses photonic‑crystal cavities that exhibit optical bistability, outperforming traditional Fabry‑Perot etalons, and enable efficient second‑harmonic generation at very low input powers. We show that the nonlinear susceptibility of materials can be strongly modified via the Purcell effect in resonant cavities.

Abstract

<a href="http://oe.osa.org/virtual_issue.cfm?vid=36">Focus Serial: Frontiers of Nonlinear Optics</a> Nonlinear photonic-crystal microresonators offer unique fundamental ways of enhancing a variety of nonlinear optical processes. This enhancement improves the performance of nonlinear optical devices to such an extent that their corresponding operation powers and switching times are suitable for their implementation in realistic ultrafast integrated optical devices. Here, we review three different nonlinear optical phenomena that can be strongly enhanced in photonic crystal microcavities. First, we discuss a system in which this enhancement has been successfully demonstrated both theoretically and experimentally, namely, a photonic crystal cavity showing optical bistability properties. In this part, we also present the physical basis for this dramatic improvement with respect to the case of traditional nonlinear devices based on nonlinear Fabry-Perot etalons. Secondly, we show how nonlinear photonic crystal cavities can be also used to obtain complete second-harmonic frequency conversion at very low input powers. Finally, we demonstrate that the nonlinear susceptibility of materials can be strongly modified via the so-called Purcell effect, present in the resonant cavities under study.